Sometimes you have to do what the client needs, not what they ask for (Because they sometimes don't have enough experience, knowledge, etc. to know. That's why they hired you, the expert).
But, this sounds very clearly unneeded feature they client does not want, will not help them, and would be wasting their money to implement.
Even without the coffee excuse, startup time for something that starts up once or even a few times day is going to be low on the bang per buck backlog.
Sometimes you have to do what the client needs, not what they ask for (Because they sometimes don't have enough experience, knowledge, etc. to know. That's why they hired you, the expert).
But, this sounds very clearly unneeded feature they client does not want, will not help them, and would be wasting their money to implement.
Even without the coffee excuse, startup time for something that starts up once or even a few times day is going to be low on the bang per buck backlog.